Hydraulic jack



April 12, 1949. LIGHTBURN 2,466,815

HYDRAULIC JACK Filed Aug. 10, 1945 2 Sheets-Sheet 2 UL! Ll W f j] 41 i 1 1 4 i 11 l 9 I, 10

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HAeo L ANDErtTw UeHTBuRN \NVENTOE Patented Apr. 12, 1949 HYDRAULIC J'AcK Harold Anderton Lightburn, "Henley Beach South, South Australia, Australia Application August 109-1 945, Serial No.'609,973 In Australia August 28, 1944 Claims.

This invention relates to improvements in hydraulic jacks, and in particular it relates to improvements in the housing of jacks and to the control mechanism whereby the jack is actuated.

An object of the invention is to dispose the mechan-ism'of the jack in an improved housing which will give a neat appearance and which will at the same time allow for the mechanism to be simply "and effectively'assembled, and which also forms-an oil reservoir in which all working parts are immersed, a further object being the construction of the mechanism itself in such a manner that the jack can be located under its load, raised and lowered entirely by manipulation of the-handle without removing the handle from the jack, the operating handle actuating the plunger which operates the ram of the jack and also the release whereby the ram is lowered as well as positioning the jack under the load.

Themechanism comprises a main ram cylinder in which is disposed the lifting ram, this cylinder being in communication with a valve block which carries the cylinder of the operating plunger, the handle which allows operation of the plunger being engaged in the main housing of the jack and being linked to the plunger in such a manner that up and down movement of the handle actuates the plunger but when the handle is partlywithdrawn it may be actuated to remove the plunger to eflect the release of a valve which allows'the ram of the jack to be lowered by permitting the oil or other hydraulic fluid to be displaced from beneath the ram back into the housing which encloses the mechanism.

The housing itself is constructed to completely P enclose the entire mechanism excepting the handle and the ram, and is preferably of allwelded construction so that the mechanism is sealed in when it has been assembled.

--In order however that the invention may be more clearly understood it will now be described with-reference to the accompanying drawings in which:

'Fig. 1 is a side elevation of a hydraulic jack constructed according to this invention,

Fig. 2 is a plan of same,

Fig. 3 is a central vertical section through the jack," on line 33 of Fig. 4,

Fig. 4 is a sectional plan of the jack as on line 4 4 of Fig. 3, and

'Fig. 5 is a sectional side elevation showing the plunger assembly.

'The jack comprises a lifting ram l disposed in a cylinder 2 and provided with a cup washer 3 of any usual or approved construction.

The cylinder is welded at its top 4 and at its beset to its supporting means, these comprising ahousi'n'g 6 upon a base plate I, the housing being Welded at 8 to the base plate I.

The "housing '6 has an integral extension 5! in which is'disposed the cylinder lll of the operat- 2 ing plunger pump, the plunger H having-atits upper end a socket 12 into which thehandle M of the jack is adapted to be engaged. The plunger ll is of'hardened steel and has labyrinth grooves t3 to minimise oil leakage.

A hydraulic seal 15, which surrounds "the top of the*plunge'r l Land which is rigidly'secur'ed in "a socket H5 in the extension 9 of the'housing- 'fi, prevents egress of the hydraulic fluids "at this locality. A guide block H in the socket"l6 forms a guide for theplunger ll.

Secured uponthe base plate '7 is a valve-block l8 which has in it-a main bore 19 through which the cylinder ill is placed into communication with the'inside o'f'th'e cylinderlthepat'h of the hydraulic fluid being through the channel!!! into the bore l9 and from the bore l'9 through the channel "2 I to the cylinder 2 Theb'ore l9 has at'its inlet'end a ball 24"which is'arrangedto prevent the hydraulic fluid from passing back from the cylinder 2 to the'pump cylinder Ill, the ball "24 being loaded 'by means of a spring 25 which tendsto'hold same on seat.

A channel '21, which communicates with the channel 20, allows the hydraulic fluid to be drawn to beneath the piston I I, the channel 'Z'Ih'aVing Within it a ball 28 which allows the flow bf hydraulic fluid to take place only in 'an'inward direction so that wh'enthe fluidisdl'awn into the cylinder Ill beneath the piston H it can billy leave this space'past the ball "24 to the "cylinder 2. The channel Ellis elongated or 'duplicate'd'tb prevent the ball 28 "from blockingthe newer liquid inward to the cylinder l 0.

The'bore I9 is also in communication withthe inside of the housing 6 through a channel 3'0 whichhas in it a ball 3i arranged'to allow -'tlie fluid from the cylinder 2 to lift same, but this ball 3! is normally held down on to its seating thepIatform 32 of a lever 33 whichis pivotedat 34 to the block Ill. The platform 32 is formed as an integral part of the lever 33. N I Disposed between the top of the lever 33 and the cylinder 2 is a spring 35 which normally maintains sufiicient pressure on the lever to hold the ball *3! on to its seat so long as the pressure within the jack does not exceed 'a safe value. The spring causes the ball 3| to act as a'sa'fet'y valve to release the fluid from the'pres'surecircuit when this pressure reaches the maximum permissible value. a

Disposed upon the plunger ll is a camlll which is adapted when the plunger H is turned about its axis, to engage a cam plate upon the lever '33 and to move this lever to release the pressure from the ball 3!. The releasing ofthe pressure from the ball 3| allows the hydraulic fluid to *life displaced from beneath the 'hy'draulicra'fn 'IQth'e fluid flowing through the channel Zl' iht'o the bore l9 and thence through the channel-30', .past

the ball 3|, back into the inside of the housing 6.

The handle I4, by means of which the plunger I I is operated, has its end projecting into a socket 45 which takes the end of the lever and provides the reaction point for the operation of the plunger II, the lever having on it a projection 46 which normally prevents same from being withdrawn through the member I2 upon the top of the plunger I I but which allows this lever to be withdrawn when such lever is revolved to make the projection 46 coincide with the major axis of the member I2. The projection 46 allows the jack to be located and removed from beneath the vehicle by the handle I4.

To operate the cam 40 to engage the cam plate 4I upon the lever 33, the handle I4 is withdrawn from the socket 45, whereupon the handle I4, is free to be swung around to revolve the plunger II about its axis and thus bring the cam into engagement with the cam plate 4|.

The hydraulic ram I is provided with an extension member 50 which may be adjusted to engage the means to be lifted prior to the raising of the ram I.

An aperture 5! through the cylinder 2 allows the hydraulic fluid to leak from beneath the ram I when this has been raised to its fullest extent, the'fluid passing from the cylinder 2 back into the inside of the housing 6 and thus to the main hydraulic fluid supply.

During construction the various parts are assembled on the base and are welded or otherwise secured into position, the housing 6 being placed over same and the unit entirely sealed, excepting that a threaded ring 53 is provided which allows the ram I to be inserted after assembly of the remaining parts, this ring allowing filling of the housing 6 with hydraulic fluid and also permitting replacement of the fluid at a later time.

A packing 52 of any suitable material is provided beneath the threaded ring 53. A spring clip 54 placed into an annular groove in the inside face of the cylinder 2, prevents the ram I from being withdrawn and also serves to locate a gland ring 55 which forms a support on which the packing may rest.

When it is desired to raise the ram I it is only necessary to actuate the handle I4 to reciprocate the plunger II, this causing hydraulic fluid to be drawn through the channel 21 from the inside of the housing 6, such fluid passing beneath the plunger I l and being ejected therefrom past the ball 24 into the bore I9 and then through the channel 2I into the base of the cylinder 2, the forcing of the hydraulic fluid into this cylinder 2 gradually raising the ram I.

When it is desired to allow the ram to return, it is only necessary to manipulate the handle I4 to disengage its ends from the socket 45 whereupon the lever 33 can be swung back by revolving the plunger II to engage the cam 40 with the cam plate 4I upon the lever, this action compressing the spring 35 and bringing the platform 32 away from the ball 3| and thereby allowing the hydraulic fluid to return from the cylinder 2 through the channel 2| into the bore I9 and then through the channel 35 past the ball 31 back into the inside of the housing 6. Downward movement of the ram I is limited by the projection 51 which contacts with the base I of the jack. A filter 58, secured over the mouth of the channel 21, restrains any solids which might otherwise be drawn into the pressure circuit by the action of the plunger II.

It will be noted that the plunger I I is not provided with any cup washer but utilizes labyrinth grooves I3 to limit the leakage past the plunger, this arrangement giving better operation and preventing air locks commonly met with in hydraulic jacks.

What I claim is:

1. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a main cylinder within such housing, a lifting ram in the cylinder, a pump cylinder, a rotatable operating plunger in the pump cylinder, a socket on the housing, a socket on the plunger, a handle arranged to pass through the socket on the plunger and engage the socket on the housing to reciprocate the plunger but withdrawable from the socket on the housing to rotate the plunger, valve means to control the flow of the hydraulic fluid from the housing into the pump and main cylinder, a release valve, and means on the plunger to actuate the release valve when the plunger is revolved.

2. An improved hydraulic jack according to claim 1 characterised by stop means on the handle to limit Withdrawal of the handle through the socket on the plunger.

3. An improved hydraulic jack comprising a housing arranged to contain a hydraulic liquid, a vertical main cylinder within said housing, a lifting ram slidable in said cylinder, a pump including a vertical pump cylinder, a plunger reciprocal and rotatable in said pump cylinder, and a handle for operating said plunger from the outside of said housing to reciprocate or rotate the same, a valve block in said housing joining said main cylinder to the pump cylinder at the lower ends of both said cylinders, said valve block having channels and valves to control the flow of the hydraulic liquid from said housing into said pump and main cylinder, a ball valve controlling a return passage from said main cylinder through said valve block into said housing and cooperating with a valve seat formed in said valve block, said ball valve being urged toward its open position by the hydraulic pressure in said main cylinder, a lever pivoted to said valve block and having a portion near its pivot point to cooperate, in one position of said lever, with said ball valve so as to keep the latter closed, a spring resting with one end thereof against said main cylinder and acting with its other end on a point of said lever remote from its pivot point to urge the lever into its valve closing position with a force sufiicient to normally prevent opening of the ball valve unless the load acting on said ram exceeds a maximum permissible value whereby said ball valve operates as a safety valve, and cam means on said plunger arranged for cooperation with a portion of said lever remote from its pivot point to displace said lever positively from its valve closing position against the action of said spring when said plunger is rotated, whereby said return valve operates as a release valve.

4. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a main vertical cylinder within such housing, a lifting ram in the cylinder, a vertical pump cylinder, a rotatable operating plunger in the pump cylinder, a socket on the housing, a socket on the plunger, a handle arranged to pass through the socket on the plunger and engage the socket on the housing to reciprocate the plunger but withdrawable from the socket on the housing to rotate the plunger, a valve block joining the main cylinder to the pump cylinder, channels and valves in the block to control the flow of the hydraulic liquid from the housing into the pump and main cylinder, a release valve in the block, and means on the plunger inside of the housing to actuate the release valve when the plunger is revolved.

5. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a main vertical cylinder within such housing, a lifting ram in the cylinder, a vertical pump cylinder, a plunger in the pump cylinder, a socket on the housing, a socket on the plunger, a handle arranged to pass through the socket on the plunger and engage the socket on the housing to reciprocate the plunger but withdrawabl from the socket on the housing to rotate the plunger, a valve block joining the main cylinder to the pump cylinder, channels and valves in the block to control the flow of the hydraulic liquid from the housing into the pump and main cylinder, a release valve in the block, spring loading means for release valve to act as a safety valve, and cam means on the plunger inside of the housing to actuate the release valve when the plunger is revolved.

6. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a main vertical cylinder within such housing, a lifting ram in the cylinder, a vertical pump cylinder also in such housing, a rotatable operating plunger in the pump cylinder said plunger projecting from the housing, a handle, a socket on the housing in which to engage the handle, means on the plunger to slidably engage the handle said means allowing the plunger to be rotated by the handle when same is withdrawn from the socket on the housing, a valve block joining th main cylinder to the pump cylinder, channels in the block, ball valves to control the flow of the hydraulic liquid through the channels from the housing into the pump and main cylinder, a release Valve in the block, and means on the plunger inside of the housing to actuate th release valve when the plunger is revolved.

7. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a main vertical cylinder within such housing, a lifting rain in the cylinder, a vertical pump cylinder also in such housing, a rotatable operating plunger in the pump cylinder said plunger projecting from the housing, a handle, a socket on the housing in which to engage the handle, means on the plunger to slidably engage the handle, said means allowing the plunger to be rotated by the handle when same is withdrawn from the socket on the housing, a valve block joining the main cylinder to the pump cylinder, channels in the block, ball valves to control the flow of hydraulic fluid through the channels from the housing into the pump and main cylinder, a release valve in the block, a member pivoted to the block in contact with the release valve, a spring between the pivoted member and the main cylinder to cause the release valve to act as a safety valve, and means on the plunger inside of the housing to displace the pivoted member against the action of the spring when the plunger is revolved.

8. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a base welded to the housing, a main cylinder within such housing welded to the base and housing, a lifting ram in the cylinder, a valve block on the base, a pump cylinder secured to th valve block and disposed within the housing, a plunger in the pump cylinder projecting from the housing, a seal between the plunger and the housing, a socket on the housing, a socket on the plunger, a handle arranged to pass through the socket on the plunger and engage the socket on the housing to reciprocate the plunger but withdrawable from the socket on the housing to rotate the plunger, channels and valve means in the valve block to control the fiow of the hydraulic liquid from the housing into the pump and main cylinder, a release valve also in the valve block, and cam means on the plunger inside of the housing to actuate the release valve when the plunger is revolved.

9. An improved hydraulic jack comprising: a housing arranged to contain a hydraulic liquid, a base welded to the housing, a main cylinder within such housing welded to the base and housing, a lifting ram in the cylinder, a valve block on the base, a pump cylinder secured to the valve block and disposed within the housing, a plunger in the pump cylinder projecting from th housing, a seal between the plunger and housing, a socket on the housing, a socket on the plunger, a handle arranged to pass through the socket on the plunger and engagethe socket on the housing to reciprocate the plunger but withdrawable from the socket on the housing to rotate the plunger, channels and valve means in the valve block to control the flow of the hydraulic liquid from the housing into the pump and main cylinder, a release valve also in the block, spring loading means for the release valve to act as a safety valve, and cam means on the plunger inside of the housing to actuate the release Valve when the plunger is revolved.

10. An improved hydraulic jack comprising; a housing arranged to contain a hydraulic liquid, a base welded to the housing, a main cylinder within such housing welded to the base and housing, a lifting ram in the cylinder, a valve block on the base, a pump cylinder secured to the valve block and disposed within the housing, a plunger in the pump cylinder projecting from the housing, a seal between the plunger and housing, cam means on the plunger, a socket on the housin ,a socket on the plunger, a handle arranged to pass through the socket on the plunger and engage the socket on the housing to reciprocate the plunger but withdrawable from th socket on the housing to rotate the plunger, channels and ball valves in the block to control the flow of the hydraulic liquid from the housing into the pump and main cylinder, a ball release valve in the valve block, a pivoted member in contact with the release valve ball, said member being in th path of the cam means on the plunger, and spring means engaging the pivoted member to normally hold the ball valve closed.

HAROLD ANDERTO-N LIGHTBURN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,455,224 Paoli May 15, 1923 1,706,309 Miller Mar. 19, 1929 2,018,506 Walker Oct. 22, 1935 2,107,970 Wells Feb. 8, 1938 2,211,479 Pomeroy Aug. 13, 1940 FOREIGN PATENTS Number Country Date 779,468 France Jan. 14, 1935 

